Damping element for use in semiconductor technology systems

Abstract

The invention relates to a damping element (200) for use in semiconductor technology systems and to a semiconductor technology system comprising a corresponding damping element (200). The damping element (200) comprises an outer shell (210), which forms the exterior of the damping element (200) and is made of a gas-tight material, and an inner tube (220), which forms the flow channel for a liquid and is made of a flexible material. The outer shell (210) and the tube (220) are connected together at the two ends of the damping element (200) such that a continuous gas volume (240) is formed between the outer shell (210) and the tube (220), at least one storage volume (250) which is fluidically connected to the gas volume (240) being provided for an accumulating liquid such that at least part of the accumulating liquid reaches the at least one storage volume (250) in order to slow the filling process of the gas volume (240). The semiconductor technology system comprises a temperature-control system (100) having at least one fluid line (101), a damping element (200) according to the invention being provided in at least one fluid line (101).

Description

30.07.2025 / BR Damping element for use in systems for cable ladder technology

[0001] The present application claims priority over German patent application 10 2024 207 791.7, filed on August 15, 2024. The content of that German patent application is incorporated into the present application text by reference.

[0002] The invention relates to a damping element for use in semiconductor technology systems and to a semiconductor technology system comprising a corresponding damping element.

[0003] In the prior art, semiconductor technology equipment refers to equipment used for the production or testing of micro- or nanostructured devices or the components required for their production. An example of such equipment is a projection exposure system for photolithography.

[0004] Photolithography is used to manufacture micro- and nanostructured components, such as integrated circuits. The projection exposure system used comprises an illumination system and a projection system. The image of a mask (also called a reticulum) illuminated by the illumination system is projected in a reduced size onto a substrate, such as a silicon wafer, coated with a photosensitive layer and positioned in the image plane of the projection system. This transfers the mask structure onto the photosensitive coating of the substrate.

[0005] Both in lighting systems and in projection systems, especially those for the EUV sector Projection exposure systems designed for exposure wavelengths from 5 nm to 30 nm typically employ several optical elements, particularly mirrors, to achieve the desired image of the mask onto the substrate. Due to the required accuracy, it is crucial, especially in projection systems, to ensure that the position of the individual optical elements relative to each other, as well as to the mask and the substrate, changes only within extremely small tolerances, if at all, during operation of the projection exposure system. Furthermore, the shape of the optical elements, particularly the mirror surfaces, must not change, or only within a predetermined range. Any change in the position and / or shape of one or more optical elements can lead to a decrease in the image quality of the projection system.

[0006] Corresponding changes in the position and / or shape of one or more optical elements can occur due to heat input into the optical elements or into the structure supporting them. Such heat input inevitably occurs, for example, due to absorption of the illumination radiation by the optical elements, absorption of interfering radiation, particularly in the infrared range, and the heat loss from electrical components in the projection system. To compensate for changes in the position of the optical elements to a certain extent, electrical actuators are known, which, however, themselves emit heat.

[0007] To avoid or at least minimize changes in the shape of the optical elements from a target shape and to dissipate heat introduced into the projection exposure system, in particular its projection system, it is known to modify at least part of the optical elements and / or other components of the projection exposure system. and in particular to provide the projection system with fluid channels for the passage of a temperature control fluid – especially demineralized water. The fluid channels, particularly in optical elements, are generally integrated directly into the structure of the optical elements, often in the form of channel-shaped openings that run internally within the structure of the optical element.

[0008] Even though the temperature of the individual components can be well regulated by means of the passage of a temperature control fluid through parts of the projection exposure system, so that changes in the position and / or shape of one or more optical elements due to heat input can be reduced or even completely avoided, it has been shown that the passage of temperature control fluid through the fluid channels provided for this purpose introduces vibrations into the components of the projection exposure system, which can lead to a decrease in image quality, especially if they occur in the projection system.

[0009] The causes of these vibrations introduced by the temperature control fluid include flow-induced vibrations (FIV), which result from the interaction of turbulent flow with the wall of the fluid channel. Undesirable vibrations also arise from waterline acoustics (WLA), where vibrations from mechanical machines, such as a circulation pump, propagate along the pipe through the temperature control fluid, similar to sound in air.

[0010] To reduce duct acoustics, it is known to design a section of the flow channel for the temperature control fluid from a viscoelastic material, with this section then being surrounded by a free gas space. Pressure fluctuations in the temperature control fluid can then be dampened. They are absorbed and dampened by elastic deformations of the hose wall.

[0011] A common design of such a damping element in semiconductor technology equipment is a gas-tight corrugated hose with an inner elastic tube surrounded by a sealed gas space. The corrugated hose serves to connect fluid channels in various components of a semiconductor technology system. Due to its deformability, manufacturing and assembly tolerances of the components to be connected by the corrugated hose can be compensated for. Since the corrugated hose is gas-tight to the environment, it can also be used in evacuated areas where a vacuum or very low pressure prevails during operation of the semiconductor technology system.

[0012] It has been shown that when using such a corrugated hose, particularly in semiconductor technology facilities and especially in areas that are evacuated during operation, liquid accumulates in the gas space. As the gas space fills with liquid, the damping effect of the corrugated hose on line acoustics decreases. At the latest when the area intended as the gas space is completely filled with liquid, sufficient line acoustic damping is no longer achieved.

[0013] The object of the present invention is to create a damping element and a system for semiconductor technology comprising a damping element in which the damping effect of the damping element for line acoustics is maintained permanently or at least for the longest possible period of time.

[0014] This problem is solved by a damping element according to claim 1, and by a system for semiconductor technology according to claim 14. Advantageous further developments are the subject of the dependent claims.

[0015] Accordingly, the invention relates to a damping element for use in semiconductor technology equipment, comprising an outer shell made of gas-tight material forming the outside of the damping element and an inner hose made of flexible material forming the flow channel for a liquid, wherein the outer shell and hose are connected to each other at the two ends of the damping element in such a way that a continuous gas volume is formed between the outer shell and the hose, wherein at least one reservoir volume is fluidly connected to the gas volume in such a way that, in order to slow down the filling of the gas volume, the accumulating liquid at least partially enters the at least one reservoir volume.

[0016] The invention further relates to a system for semiconductor technology comprising at least one temperature control system, wherein a damping element according to the invention is arranged in at least one fluid line of the temperature control system.

[0017] First, some terms used in connection with the invention will be explained.

[0018] A gas volume formed between two elements is considered "continuous" if the two elements contact only along continuous lines around the circumference of the gas volume. Apart from this contact, which forms the boundary of the gas volume at the respective points, there is no structural contact between the two elements.

[0019] Two volumes are “fluidly connected” if they are connected in such a way that a fluid, especially a liquid, can flow from one volume into the other.

[0020] A "fluid line" is a conduit for conveying fluids whose characteristic cross-sectional area is smaller than the length of the fluid line. The characteristic cross-sectional area can be, for example, the diameter for a circular cross-section, the length of the diagonals for a rectangular cross-section, or the square root of the free flow cross-section (i.e., the cross-sectional area available for the flow) for cross-sections of any shape. The length refers to the length of the fluid line with a substantially constant cross-section. Fluid lines can be, in particular, tubular or hose-like.

[0021] A volume is "geodesically arranged below" a fluid-connected volume if a fluid, in particular a liquid, can flow into the former volume solely by gravity, at least after reaching a predetermined minimum fill level in the latter volume, provided the fluid connection is suitably designed. The "minimum fill level," at least in the case of a liquid, is generally dependent on the arrangement and design of the fluid connection, especially its connection to the latter volume. In particular, liquid can only flow through such a connection once the liquid level has reached the connection point.

[0022] A connection is "geodesically downward" if fluid, especially liquid, generally flows towards the connection due to gravity and the minimum fill level is minimal. The opening of a geodesically downward-positioned connection The connection can be arranged in particular perpendicular to the direction of gravity in the area of ​​the opening.

[0023] The invention recognizes that the gas volume of a damping element with an internal elastic hose fills, or can fill, with liquid due to the permeation of a liquid conveyed through the hose wall and the subsequent condensation of the initially gaseous permeate. This permeation is driven by the partial pressure difference for the liquid on both sides of the hose wall. On the liquid-carrying side, the equilibrium vapor pressure of the liquid can be assumed as the partial pressure. The partial pressure for the liquid that ultimately establishes itself in the gas volume, at least after an initial start-up phase, is the saturation vapor pressure. If the saturation vapor pressure is exceeded, the liquid condenses and collects in the gas volume.

[0024] By providing, according to the invention, at least one holding volume, which is fluidly connected to the gas volume of the damping element in such a way that any liquid that would otherwise accumulate at least partially enters the holding volume, the time until the gas volume fills with liquid to such an extent that the damping effect of the damping element decreases beyond an acceptable level with regard to line acoustics is extended. Specifically, because a portion of the liquid that would otherwise accumulate in the gas volume collects in the holding volume or flows from the gas volume to it, the gas volume fills with liquid more slowly than in the prior art. In other words, the filling of the gas volume with liquid is slowed down.

[0025] Basically, two mechanisms of action can lead to at least partial accumulation of fluid in at least one The effects of holding volumes are as follows: Firstly, the liquid, initially present in the gas phase or as vapor in the gas volume, can pass through the fluid connection into at least one holding volume, where it then condenses. Because at least some of the gaseous or vaporous liquid inevitably present in the gas volume condenses not there, but in the at least one holding volume, the liquid accumulation in the gas volume is slower. Secondly, liquid that has already condensed in the gas volume can pass through the fluid connection in liquid form from the gas volume into at least one holding volume, thus generally keeping the liquid level in the gas volume constant until the at least one holding volume is completely filled. This also ensures that the damping effect of the damping element can be maintained for a longer period.The liquid can flow through the fluid connection into the holding volume due to gravity. Alternatively or additionally, the fluid connection can be designed so that the liquid or permeate is transported from the gas space into the holding volume by capillary action (possibly even against gravity). This also applies comparably to fluids in the gaseous or vaporous state.

[0026] It is of course possible for several of the aforementioned mechanisms to act in parallel within a single damping element. Depending on the design and arrangement, the first-mentioned mechanism may act first for a given buffer volume, followed by the last-mentioned mechanism. It is also possible to provide multiple buffer volumes, at least one of which is designed for the first-mentioned mechanism, and at least one other for the last-mentioned mechanism.

[0027] The storage volume can be connected to the gas volume over a large area. In particular, it can be designed as an extension of the gas volume.

[0028] However, it is preferred if the storage volume is connected to the gas volume by one or more fluid lines. It is particularly preferred that the at least one fluid line has a free flow cross-section of 0.8 mm². 2up to 2000 mm 2 , preferably of 0.8 mm 2 up to 700 mm 2 , preferably from 0.8 mm 2 up to 300 mm 2 If fluid transport through a fluid line is to be effected by capillary effects, a corresponding fluid line can have a free flow cross-section of 0.001 pm. 2 down to 0.2 mm 2The buffer volume is connected to the gas volume only by one or more fluid lines, particularly with the specified flow cross-sections. By providing the buffer volume, the fundamental configuration of the gas volume does not need to be changed, thus minimally disturbing the known basic processes within the gas volume. Therefore, the design of the damping element can generally be based on relationships known from the prior art. This applies particularly if the fluid lines are primarily intended to discharge liquid that has already condensed in the gas volume into the buffer volume.

[0029] Regardless of whether the buffer volume is connected to the gas volume via fluid lines, at least one buffer volume can be directly integrated into the damping element. This can be achieved by integrating a buffer volume into an existing component, such as connecting elements at the ends of the damping element for attaching it to fluid lines, by creating, for example, a fluid-connected cavity within it that is connected to the gas volume. The component in question can It may also be suitable for creating a cavity large enough for the storage volume.

[0030] It is also possible that at least one buffer volume is designed separately from the damping element and connected to the gas volume via a rigid fluid line. If at least one buffer volume is connected to the gas volume via a rigid fluid line, e.g., a pipe, it forms a unit with the damping element, in which it generally does not need to be separately fastened, but is permanently fixed in place relative to the damping element via the rigid fluid line and is thus sufficiently secured by the connection of the damping element to the lines to be connected.

[0031] Furthermore, it is possible for the holding volume to be designed separately from the damping element and connected to the gas volume via a fluid line that is at least partially flexible. If the fluid line is at least partially flexible, the holding volume is not directly attached to the damping element but requires its own attachment; however, the holding volume can then be positioned as desired, and in particular, at a distance from the damping element. The latter is especially advantageous when there is limited space available for the damping element. The holding volume can also be positioned in an easily accessible location if temporary emptying of the holding volume (see below) is to be permitted.

[0032] Particularly when connecting a holding volume via a fluid line, especially a partially flexible fluid line, it is preferred if at least one holding volume is arranged geodesically below the gas volume. Such an arrangement prevents the gravity-induced outflow of any precipitate already present in the gas volume. This facilitates the flow of liquid into the appropriately arranged storage volume. In particular, this usually eliminates the need for active conveying elements such as pumps, etc.

[0033] It is preferred if at least one connection of a fluid line to a holding volume, in particular to a holding volume arranged geodesically below the gas volume, is arranged geodesically at the bottom of the gas volume. This ensures that any liquid that has precipitated in the gas volume will generally, and especially even at a minimal fill level in the gas volume, flow into the fluid line in question and from there into a holding volume solely by gravity. The fill level in the gas volume can thus be kept minimal at least until all correspondingly connected holding volumes are completely filled.

[0034] Alternatively or additionally, at least one storage volume can be geodesically located above the gas volume, and / or at least one connection of a fluid line to a storage volume, in particular to a storage volume arranged geodesically above the gas volume, can be geodesically located at the top of the gas volume. With a corresponding arrangement of storage volume and connections, gaseous permeate can be discharged from the gas space or enter a storage volume. If the fluid line has a sufficiently small free flow cross-section, liquid permeate can also be conveyed into a storage volume by capillary action.

[0035] It is preferred if at least one storage volume is designed to be emptied. During regular maintenance and / or when a predetermined fill level is reached, the corresponding storage volume can be emptied to make it ready to receive more liquid. In this context, "emptyable" means that... The system allows liquid to be removed from the holding volume without having to completely disassemble the damping element. For example, a component separate from the damping element, containing the holding volume, can be designed to be easily replaceable. This allows the component in question to be replaced with another suitable component after disassembly, or it can be reinserted after emptying. The holding volume can also have a drain connection through which liquid can be drained or extracted.

[0036] The at least one reserve volume, or the sum of the reserve volumes, is preferably selected such that the damping effect of the damping element for line acoustics is maintained to a predetermined extent for a given period. The at least one reserve volume is therefore designed such that no liquid level in the gas volume develops over the given period at which the damping effect is no longer present to the desired or required extent. This period can be the expected service life for which the damping element is intended. If at least part of the reserve volume is designed to be drained, the period can also be the time between two regular maintenance intervals, during which the corresponding reserve volumes are then to be drained. The at least one reserve volume, or...The sum of all storage volumes of a damping element can preferably be at least half, preferably at least as large as, the gas volume. Preferably, the factor of the sum of all storage volumes compared to the gas volume (or the volume ratio of storage volume and gas volume) can be 0.1 to 10, preferably 0.5 to 5, more preferably 0.5 to 2.

[0037] The damping element can be designed, in particular, as a corrugated tube, in which the outer shell is a flexibly deformable bellows made of rigid, gas-tight material with a wave-like, alternating diameter. Besides its function as a damping element, a corrugated tube is regularly suitable for compensating for manufacturing and assembly tolerances of components in semiconductor technology systems connected by the corrugated tube. However, it is also possible for the outer shell to be designed as a rigid, smooth tube or a combination of a flexibly deformable bellows and a rigid, smooth tube, which can alternate in certain sections.

[0038] For an explanation of the inventive system for semiconductor technology, reference is made to the preceding explanations. The system comprises a temperature control circuit in which a damping element according to the invention is arranged at least at one location. The damping element serves as a damper for line acoustics and retains this functionality permanently due to the inventive design of the damping element, which has been explained in detail above.

[0039] Water, and more preferably fully demineralized water, is preferably used as the liquid for the temperature control circuit and thus for passage through the at least one damping element according to the invention.

[0040] The invention will now be described by way of example with reference to advantageous embodiments and the accompanying drawings. These show: Figure 1: a schematic representation of a projection exposure system for photolithography; Figure 2: a detail of Figure 1; and Figure 3a-c: schematic representations of different design variants of the damping element of the system according to Figures 1 and 2.

[0041] Figure 1 shows a schematic meridional section of a projection exposure system 1 for photolithography as an example of a system for semiconductor technology. The projection exposure system 1 comprises an illumination system 10 and a projection system 20.

[0042] The illumination system 10 illuminates an object field 11 in an object plane or reticulum plane 12. The illumination system 10 comprises an illumination radiation source 13, which, in the illustrated embodiment, emits illumination radiation comprising at least useful light in the EUV range, i.e., in particular with a wavelength between 5 nm and 30 nm. The illumination radiation source 13 can be a plasma source, for example, an LPP source (laser-produced plasma) or a DPP source (gas-discharge-produced plasma). It can also be a synchrotron-based radiation source. The illumination radiation source 13 can also be a free-electron laser (FEL).

[0043] The illumination radiation emanating from the light source 13 is first focused in a collector 14. The collector 14 can be a collector with one or more ellipsoidal and / or hyperboloid reflective surfaces. The at least one reflective surface of the collector 14 can be illuminated at grazing incidence (Gl), i.e., with angles of incidence greater than 45°, or at normal incidence (NI), i.e., with angles of incidence less than 45°. The collector 14 can, on the one hand, be used for... Its reflectivity should be optimized for useful radiation and, on the other hand, structured and / or coated to suppress stray light.

[0044] After the collector 14, the illumination radiation propagates through an intermediate focus in an intermediate focal plane 15. If the illumination system 10 is to be constructed in a modular manner, the intermediate focal plane 15 can, in principle, be used for the separation – including structural separation – of the illumination system 10 into a radiation source module, comprising the exposure radiation source 13 and the collector 14, and the illumination optics 16 described below. With such a separation, the radiation source module and the illumination optics 16 then together form a modularly constructed illumination system 10.

[0045] The illumination optics 16 include a deflecting mirror 17. The deflecting mirror 17 can be a planar deflecting mirror or, alternatively, a mirror with an effect that influences the beam shape beyond the mere deflection effect. Alternatively or additionally, the deflecting mirror 17 can be designed as a spectral filter that separates a useful wavelength of the illumination radiation from stray light of a different wavelength.

[0046] The deflecting mirror 17 deflects the radiation from the illumination radiation source 13 onto a first faceted mirror 18. If the first faceted mirror 18 is arranged – as in the present case – in a plane of the illumination optics 16 that is optically conjugate to the reticular plane 12 as the field plane, it is also referred to as a field faceted mirror.

[0047] The first faceted mirror 18 comprises a multitude of individually arranged facets, each with two perpendicular edges. Axes pivotable micromirrors 18' for the controllable formation of facets, each preferably equipped with an orientation sensor (not shown) for determining the orientation of the micromirror 18'. The first faceted mirror 18 is thus a microelectromechanical system (MEMS system), as described, for example, in DE 10 2008 009 600 A1.

[0048] In the beam path of the illumination optics 16, a second faceted mirror 19 is arranged downstream of the first faceted mirror 18, resulting in a double-faceted system, the basic principle of which is also known as a honeycomb condenser (Fly's Eye Integrator). If the second faceted mirror 19 is arranged in a pupil plane of the illumination optics 16 – as in the illustrated embodiment – ​​it is also referred to as a pupil faceted mirror. However, the second faceted mirror 19 can also be arranged at a distance from a pupil plane of the illumination optics 16, in which case the combination of the first and second faceted mirrors 18, 19 results in a specular reflector, as is the case, for example, with... described in US 2006 / 0132747 Al, EP 1 614 008 Bl and US 6,573,978.

[0049] The second faceted mirror 19 need not be constructed from pivotable micromirrors, but can instead comprise individual facets formed from one or a manageable number of mirrors that are significantly larger than micromirrors, and which are either fixed or tiltable only between two defined end positions. However, as shown, it is also possible to provide the second faceted mirror 19 with a microelectromechanical system comprising a plurality of micromirrors 19' that are individually pivotable about two axes perpendicular to each other, each preferably comprising an orientation sensor.

[0050] With the aid of the second faceted mirror 19, the individual facets of the first faceted mirror 18 are projected onto the object field 11, although this is regularly only an approximate projection. The second faceted mirror 19 can be the last beam-forming or even the last mirror for the illumination radiation in the beam path before the object field 11.

[0051] Each of the facets of the second faceted mirror 19 is assigned to exactly one of the facets of the first faceted mirror 18 to form an illumination channel for illuminating the object field 11. This can result in illumination according to Köhler's principle.

[0052] The facets of the first faceted mirror 18 are each imaged superimposed on a corresponding facet of the second faceted mirror 19 to illuminate the object field 11. The illumination of the object field 11 is as homogeneous as possible. It preferably exhibits a uniformity error of less than 2%. Field uniformity can be achieved by superimposing different illumination channels.

[0053] By selecting the illumination channels ultimately used, which is easily achieved by appropriately adjusting the micromirrors 18' of the first faceted mirror 18, the intensity distribution in the entrance pupil of the projection system 20 described below can be further adjusted. This intensity distribution is also referred to as the illumination setting. Furthermore, it can be advantageous not to position the second faceted mirror 19 exactly in a plane that is optically conjugate to a pupil plane of the projection system 20. In particular, the pupil faceted mirror 19 can be positioned relative to a pupil plane of the projection system 20 be arranged at an angle, as described for example in DE 10 2017 220 586 Al .

[0054] In the arrangement of the components of the illumination optics 16 shown in Figure 1, the second faceted mirror 19 is arranged in a surface conjugated to the entrance pupil of the projection system 20. Deflection mirror 17 and the two faceted mirrors 18, 19 are each tilted relative to both the object plane 12 and to each other.

[0055] In an alternative embodiment of the illumination optics 16, not shown, a transmission optic comprising one or more mirrors can be provided in the beam path between the second faceted mirror 19 and the object field 11. The transmission optic can, in particular, comprise one or two mirrors for normal incidence (NI mirrors, normal incidence mirrors) and / or one or two mirrors for grazing incidence (Gl mirrors, grazing incidence mirrors). With an additional transmission optic, different positions of the entrance pupil for the tangential and sagittal beam paths of the projection system 20 described below can be taken into account.

[0056] Alternatively, it is possible to dispense with the deflecting mirror 17 shown in Figure 1, for which the faceted mirrors 18 , 19 must then be arranged appropriately opposite the radiation source 13 and the collector 14.

[0057] With the help of the projection system 20, the object field is 11 in the reticulum plane 12 is transferred to the image field 21 in the image plane 22.

[0058] The projection system 20 comprises a plurality of mirrors Mi, which are numbered according to their arrangement in the beam path of the projection exposure system 1. The mirrors Mi are optical elements 25.

[0059] In the example shown in Figure 1, the projection system 20 comprises six mirrors Mx to M6 as optical elements 25. Alternatives with four, eight, ten, twelve, or any other number of mirrors Mi are also possible. The penultimate mirror M5 and the last mirror M6 each have an aperture for the illumination radiation, making the projection system 20 a doubly obscured optical system. The projection system 20 has an image-side numerical aperture greater than 0.3, and which can also be greater than 0.6, for example, 0.7 or 0.75.

[0060] The reflective surfaces of the mirrors Mi can be designed as freeform surfaces without an axis of rotational symmetry. Alternatively, the reflective surfaces of the mirrors Mi can also be designed as aspherical surfaces with exactly one axis of rotational symmetry of the reflective surface shape. The mirrors Mi, like the mirrors of the illumination optics 16, can have highly reflective coatings for the illumination radiation. These reflective coatings can be designed as multilayer coatings, in particular with alternating layers of molybdenum and silicon.

[0061] The projection system 20 has a large object-image offset in the y-direction between a y-coordinate of a center of the object field 11 and a y-coordinate of the center of the image field 21. This object-image offset in the y-direction can be approximately as large as a z-distance between the object plane 12 and the image plane 22.

[0062] The projection system 20 can in particular be anamorphic, i.e. it has in particular different image scales β. x , ß y in the x and y directions. The two image scales ß x , ß y of the pro-ection system 20 are preferably located at (ß x , ß y ) = ( + 0.25, / + - 0.125) . A magnification β of 0.25 corresponds to a reduction in the ratio of 4:1, while a magnification β of 0.125 results in a reduction in the ratio of 8:1. A positive sign for the magnification β indicates a magnification without image inversion, a negative sign indicates a magnification with image inversion.

[0063] Other magnification ratios are also possible. Magnification ratios with the same sign and those with the same absolute value are also possible. x , ß y In the x and y directions, adjustments are possible.

[0064] The number of intermediate image planes in the x- and y-directions in the beam path between the object field 11 and the image field 21 can be the same or different, depending on the design of the projection system 20. Examples of projection systems 20 with different numbers of such intermediate images in the x- and y-directions are known from US 2018 / 0074303 Al.

[0065] Projection system 20 can, in particular, have a homocentric entrance pupil. This may be accessible. However, it may also be inaccessible.

[0066] A reticle 30 (also called a mask) arranged in the object field 11 is exposed by the lighting system 10 and transferred to the image plane 21 by the projection system 20. The reticle 30 is held by a reticle holder 31. The reticle holder 31 can be moved, particularly in one scanning direction, by means of a reticle displacement drive 32. In the illustrated embodiment, the scan direction runs in the y-direction.

[0067] The reticule 30 can have an aspect ratio between 1:1 and 1:3, preferably between 1:1 and 1:2, and particularly preferably 1:1 or 1:2. The reticule 30 can be substantially rectangular and is preferably 5 to 7 inches (12.70 to 17.78 cm) long and wide, more preferably 6 inches (15.24 cm) long and wide. Alternatively, the reticule 30 can be 5 to 7 inches (12.70 to 17.78 cm) long and It should be 10 to 14 inches (25.40 to 35.56 cm) wide, and preferably 6 inches (15.24 cm) long and 12 inches (30.48 cm) wide.

[0068] A structure on the reticulum 30 is imaged onto a photosensitive layer of a wafer 35 located in the image plane 22 within the image field 21. The wafer 35 is held by a wafer holder 36. The wafer holder 36 can be displaced, particularly along the y-direction, via a wafer transfer drive 37. The displacement of the reticulum 30 via the reticulum transfer drive 32 and of the wafer 35 via the wafer transfer drive 37 can be synchronized.

[0069] The projection exposure system 1 shown in Figure 1, or its projection system 20, the above description of which essentially reflects known prior art, further comprises a temperature control system 100 with which various components of the projection system 20 can be kept at a set temperature, in order to avoid or at least minimize changes in the position and / or shape of the mirrors Mx to M6.

[0070] In Figure 1 and Figure 2, which is merely an enlargement of part of Figure 1, the temperature control system 100 is shown on the mirror for the sake of clarity. M4 is limited and only shown in a highly schematic way. As indicated, among other things, by the additional inlets and outlets shown with dotted lines, the temperature control system 100 can also extend to further mirrors M2, M3, M5 and / or M6, as well as other components not shown, such as, in particular, the support structure to which mirrors M2 to M6 are attached. It is also possible that the temperature control system 100 controls components of the exposure system 10. However, the exposure system 10 can also have its own temperature control system.

[0071] The temperature control system 100 comprises fluid lines 101 for conveying a temperature control medium, a circulation pump 102 for pumping the temperature control medium through the fluid lines 101, and a controllable heat / cold source as element 103 for actively temperature control of the temperature control medium. The fluid lines 101 are connected to a fluid channel 26 passing through the mirror M4 to be temperature controlled, such that a closed temperature control circuit 105 is formed for the temperature control medium.

[0072] The circulation pump 102 circulates the temperature control medium, which can be actively regulated to a desired temperature by means of element 103, along or through various components, such as the mirror M4, where heat exchange occurs, so that the corresponding components gradually approach the actively controlled temperature of the temperature control medium. This is well known in the prior art.

[0073] Element 103 for active temperature control of the temperature control medium can be provided as a heat pump with an electrically operated heating element, which is designed to provide the to supply or remove heat from a flowing temperature control medium in a heat exchanger.

[0074] To prevent vibrations from the circulation pump 102 and / or the active temperature control element 103 from being transmitted through the structure, the circulation pump 102 and / or the active temperature control element 103 are generally mechanically decoupled from the projection system 10 as much as possible and arranged at a distance from it. For this reason, the circulation pump 102 and / or the active temperature control element 103 are also regularly arranged outside the evacuable space provided for the optical elements of the projection exposure system 1. The system boundary between the evacuable space and the area with ambient conditions is indicated in Figures 1 and 2 by the dashed line 90.

[0075] In addition to the elements 101, 102, and 103 shown, the temperature control system 100 can include further elements, such as controllable valves. If several components of the projection exposure system 1 are supplied with temperature control medium in different parallel temperature control circuits 105 using the temperature control system 100, valves can be used to individually adjust the flow rate in the individual temperature control circuits 105.

[0076] All elements 101, 102, 103 of the temperature control system 100, as well as the fluid channels 26 through components of the projection exposure system 1, are designed to generate as few flow-induced vibrations as possible and to exhibit advantageously developed conduit acoustics to dampen acoustic vibrations in the temperature control medium resulting from these or other causes. However, the generation of flow-induced vibrations and conduit acoustics cannot be completely avoided.

[0077] To reduce the effects of the pipe acoustics on the mirror M4ZU, damping elements 200 are provided within the fluid lines 101. The damping elements 200 are arranged in the evacuated space and initially serve to connect the assembly around the mirror M4 to the parts of the temperature control system 100 located outside the evacuated space. Since the damping elements 200 are designed as corrugated hoses, they can compensate for assembly and manufacturing tolerances due to their deformability, as is known from the prior art.

[0078] The primary purpose of the damping elements 200 is to dampen the acoustics of the transmission lines. To illustrate this, reference is made to Figures 3a-c, which show various embodiments of the damping elements 200, designed as corrugated tubes, from Figure 2.

[0079] A damping element 200 comprises an outer shell 210, which forms the outside of the damping element 200. The outer shell 210 is made of a gas-tight material, in particular a metal such as aluminum or stainless steel. In the illustrated embodiment, the outer shell 210 has the shape of a bellows with a wave-like, varying diameter, making it deformable in order to compensate for, for example, assembly and manufacturing tolerances when connecting two fluid lines 101, as already mentioned above. However, other shapes for the outer shell 210 are also possible.

[0080] Inside the outer casing 210, a flexible hose 220, in particular a viscoelastic material, is arranged such that the actual flow of liquid through the damping element 200 occurs solely through the hose 220. Due to the viscoelastic properties of the hose 220, the damping element 200 acts as a damper for the line acoustics – at least as long as the Hose 220 is so free on its outside that it can react to “acoustic” pressure fluctuations in the fluid flowing through it by elastic deformation of the hose wall.

[0081] The outer shell 210 and the hose 220 are connected to each other in a ring-like fashion at both ends of the damping element 200 via the connecting elements 230, so that a continuous gas volume 240 is formed between the outer shell 210 and the hose 220, which completely surrounds the hose 220. The gas volume 240 is gas-tight from the surroundings.

[0082] When a liquid, such as water, especially demineralized water, is passed through the damping element 200 and thus through the inner tube 220, the gas volume 240 can fill with liquid that permeates through the tube 220 via permeation and subsequent condensation. Above a certain liquid level in the gas volume 240, the damping effect of the damping element 200 with regard to the acoustics of the line decreases beyond an acceptable level.

[0083] In order to postpone this point in time as much as possible, the corrugated hoses 200 according to figures 3a-cj each comprise a holding volume 250 which is fluidly connected to the gas volume 240 .

[0084] In the embodiment shown in Figure 3a, one of the connecting elements 230 is extended so that the storage volume 250 can be provided in it, whereby the storage volume 250 is directly integrated into the corrugated hose 200.

[0085] The connecting element 230 also includes a fluid line 260, with which the liquid is transferred from the gas volume Fluid 240 can enter the holding volume 250. The fluid line 260, for example, is circular with a diameter of 5 mm, giving it a free flow cross-section of approximately 20 mm². 2 exhibits .

[0086] If the damping element 200 is installed such that the reservoir volume 250 is geodesically located below the gas volume 240, the gas volume 240 will initially only fill to a maximum of the point where the fluid line 265 connects to the gas volume 240. Additional fluid will then flow by gravity through the fluid line 260 into the reservoir volume 250. Only when the reservoir volume 250 is completely filled with fluid will the fluid level in the gas volume 240 rise further as more fluid is added. This extends the period until the gas volume fills with enough fluid to prevent the damping effect of the damping element 200 from affecting the acoustics of the line.

[0087] Figure 3b shows an alternative embodiment of a damping element 200 according to the invention, in which the retention volume 250 extends around the outer shell 210 of the damping element 200 in a sleeve-like manner. The damping element 200 is again designed as a corrugated tube with a bellows as the outer shell 210.

[0088] The storage volume 250 is distributed via several rigid, and therefore pipe-like, fluid lines 260 with a diameter of, for example, 10 mm (and thus a free flow cross-section of 80 mm). 2 ) connected to the outer shell 210 and fluidically connected to the gas volume 240. In the illustrated embodiment, four fluid lines 260 are arranged evenly distributed around the circumference at each of the two ends of the storage volume 250. The storage volume 250 is connected to the outer shell 210 by means of the fluid lines 260. or connected to the damping element 200, so that no separate fastening of the storage volume 250 is required; on the other hand, in the illustrated embodiment, the connection is such that the function of the outer shell 210 designed as a bellows or of the damping element 200 designed as a corrugated hose for compensating for manufacturing and assembly tolerances is only minimally restricted, if at all.

[0089] While the fluid lines 260 arranged geodesically in the lower region in the assembled state of the damping element 200 function primarily in a manner comparable to the fluid line 260 of the exemplary embodiment according to Figure 3a, for which reference is made to the preceding explanations, the gas located in the gas volume 240, in which the liquid may be contained in a gaseous phase or as vapor, can also enter the storage volume 250 (especially in its geodesically upper region) through the other fluid lines 260 and condense there, in order to remain in liquid form in the storage volume 250.

[0090] In the exemplary embodiment according to Figure 3b, the size of the holding volume 250 corresponds to the size of the gas volume 240 of the damping element 200 .

[0091] Figure 3c shows another embodiment of a damping element 200 according to the invention. Here too, the damping element 200 is designed in the form of a corrugated hose. In this exemplary embodiment, two reservoir volumes 250 are provided, each designed separately from the actual damping element 200 and connected to its gas volume 240 only via, for example, hose-like fluid lines 260. The fluid lines 260 have a diameter of, for example, 10 mm and thus a free flow cross-section of approximately 80 mm². 2 .

[0092] The connections 265 of the fluid lines 260 on the outer shell 210 and the gas volume 240 are geodesically arranged at the bottom of the gas volume 240. Consequently, the liquid accumulating in the gas volume 240 flows—i.e., apart from small quantities of liquid that may collect in troughs of the undulating diameter of the outer shell 210, which is designed here as a bellows—solely by gravity through the connections 265 into the fluid lines 260 and thus into the reservoir volumes 250 arranged geodesically below the damping element 200.

[0093] Each of the storage volumes 250 has a drain connection 255 through which liquid can be drained or extracted from the storage volume 250 as needed. The storage volumes 250 are preferably arranged for easy access so that, for example, they can be easily emptied via the drain connection 255 during regular maintenance procedures. The total volume of the storage volumes 250 is selected such that they can completely absorb the liquid that precipitates from the gas volume 240 of the damping element 200 during the interval between two maintenance procedures. In the example shown, the total volume of the storage volumes 250 is slightly more than half of the gas volume. Alternatively, a partially filled storage volume 250 can be replaced by a completely empty storage volume 250. In this case, a drain connection 255 is not required. Reference symbol list Projection exposure system Lighting system Object field Object plane or reticle plane Exposure radiation source Collector Intermediate focus plane Lighting optics Deflection mirror, 19 faceted mirrors, 19 micromirrors Project system Image field Image plane, optical elements, mirror Fluid channel Reticles Label holder Reticulum transfer drive Wafer Wafer holder Wafer transfer drive 0 Temperature control system 1 Fluid line 2 Circulation pump 3 Active temperature control element 5 Temperature control circuit 0 Damping element 0 Outer casing 0 Hose 0 Connecting element 0 Through gas volume 0 Storage volume 255 Drain connection 260 Fluid line 265 Connection of a fluid line

Claims

Patent claims 1. Damping element (200) for use in semiconductor technology equipment comprising an outer shell (210) made of gas-tight material forming the outside of the damping element (200) and an inner tube (220) made of flexible material forming the flow channel for a liquid, wherein the outer shell (210) and the tube (220) are connected to each other at the two ends of the damping element (200) in such a way that a continuous gas volume (240) is formed between the outer shell (210) and the tube (220), characterized in that at least one reservoir volume (250) is fluidly connected to the gas volume (240) in such a way that the accumulating liquid at least partially enters the at least one reservoir volume (250) in order to slow down the filling of the gas volume (240).

2. Damping element according to claim 1, characterized in that the holding volume (250) is connected to the gas volume (240) by one or more fluid lines (260).

3. Damping element according to claim 2, characterized in that at least one fluid line (260) has a free flow cross-section of 0.8 mm² 2 up to 2000 mm 2 , preferably of 0.8 mm 2 up to 700 mm 2 , preferably of 0.8 mm 2 up to 300 mm 2 exhibits and / or at least one fluid line has a free flow cross-section of 0.001 pm 2 up to 0.2 mm 2 exhibits .

4. Damping element according to one of the preceding claims, characterized in that at least one retention volume (250) is directly integrated into the damping element (200).

5. Damping element according to one of the preceding claims, characterized in that at least one holding volume (250) is formed separately from the damping element (200) and is connected to the gas volume (240) via a rigid fluid line (260).

6. Damping element according to one of the preceding claims, characterized in that at least one holding volume (250) is formed separately from the damping element (200) and is connected to the gas volume (240) via an at least partially flexible fluid line (260).

7. Damping element according to one of the preceding claims, characterized in that at least one holding volume (250) is arranged geodesically below the gas volume (240).

8. Damping element according to one of the preceding claims, characterized in that at least one connection (265) of a fluid line (260) to a holding volume (250) is arranged geodesically at the bottom of the gas volume (240).

9. Damping element according to one of the preceding claims, characterized in that at least one holding volume (250) is arranged geodesically above the gas volume (240).

10. Damping element according to one of the preceding claims, characterized in that if at least one connection (265) of a fluid line (260) is arranged geodesically at the top of the gas volume (240) to a holding volume (250).

11. Damping element according to one of the preceding claims, characterized in that at least one holding volume (250) is designed to be emptied and / or replaced.

12. Damping element according to one of the preceding claims, characterized in that the factor of the sum of all storage volumes (250) relative to the gas volume (240) is 0.1 to 10, preferably 0.5 to 5, more preferably 0.5 to 2.

13. Damping element according to one of the preceding claims, characterized in that the damping element (200) is designed as a corrugated hose with a flexibly deformable bellows made of gas-tight material with a wave-like varying diameter as an outer shell (210).

14. Semiconductor technology system comprising at least one temperature control system (100) , characterized in that a damping element (200) according to one of claims 1 to 13 is arranged in at least one fluid line (101) of the temperature control system (100).

15. System according to claim 14, characterized in that the damping element (200) is arranged in the vacuum area of ​​the system for semiconductor technology.

16. System according to claim 14 or 15, characterized in that The system for semiconductor technology is a projection exposure system (1) for photolithography.

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